1. Field of the Invention
The present invention relates to a putter head which gives a sense of smooth and comfortable stroking to a golfer while allowing the golfer to hit a golf ball so that the golf ball accurately travel on an imaginary ball hitting line direction.
2. Description of the Related Art
FIG. 3 shows one type of conventionally known putter. As shown in FIG. 3, the putter includes a grip portion 99b which is adapted to be grasped by a golfer, a shaft 100 extending linearly downward from the grip portion 99b, and a putter head 99 which is connected to a distal end of the shaft 100. The putter head 99 has a laterally extending putter face on a front portion of a putter head body and a strip-like longitudinal line mark 102 which is formed on an upper surface of the putter head body and extends rearwardly from a center (so-called “sweet spot”) 23 of the putter face 22 in the direction orthogonal to the putter face 22.
Due to such a constitution, the putter allows the golfer to easily align the longitudinal line mark 102 with the imaginary ball hitting line direction 109. Further, when the above-mentioned longitudinal line mark 102 which emphasizes the longitudinal direction becomes long and conspicuous in the imaginary ball hitting line direction 109, the alignment of the longitudinal line mark 102 with the imaginary ball hitting line direction 109 maybe facilitated. However, in an actual putting operation to take back the putter head 99 straightly parallel to the imaginary ball hitting line direction 107 and, thereafter, to swing the putter head 99 forward straightly parallel to the imaginary ball hitting line direction 109, the larger the take-back or the follow-through becomes, the swing stroke is liable to take an arcuate trajectory 110 in a horizontal plane as shown in FIG. 3. In this case, the longer and the more conspicuous the longitudinal line mark 102, the inclination of the longitudinal line mark 102 with respect to the imaginary ball hitting line direction 109 at the take-back position and the follow-through position is increased and hence, the golfer tends to easily recognize the inclination of the longitudinal line mark 102 with his/her naked eyes. Accordingly, the golfer strongly feels the arcuate swinging of the putter head 99 on the horizontal plane due to the inclination and this feeling damages his/her image to perform the stroke parallel to the imaginary ball hitting line direction 109.
FIG. 4 shows another type of conventionally known putter. Here, a putter head 99a has a laterally extending putter face on a front portion of a putter head body and two circular marks 105, 105 which have the same diameter and are formed on an upper surface of the putter head body and are arranged rearwardly in a spaced-apart manner from a center (so-called “sweet spot”) 23 of the putter face 22 in the direction orthogonal to the putter face 22.
Due to such a constitution, the putter allows the golfer to easily align an imaginary center line of two circular marks 105 with the imaginary ball hitting line direction 109. Further, when the above-mentioned circular marks 105 which emphasizes the longitudinal direction becomes more conspicuous by coloring, the alignment of the circular marks 105 with the imaginary ball hitting line direction 109 may be facilitated. However, as described previously in conjunction with FIG. 3, in the actual putting operation to take back the putter head 99a straightly parallel to the imaginary ball hitting line 109 and, thereafter, to stroke the putter head 99a forward straightly parallel to the imaginary ball hitting line direction 109, the larger the take-back stroke or the follow-through stroke becomes, the stroke is liable to take an arcuate trajectory 110 on a horizontal plane as shown in FIG. 4. In this case, two profile lines 107 of the putter head body are arranged parallel to the imaginary ball hitting line direction 109 and, at the same time, two tangential lines 108 which connect circumferential portions of two circular marks 105, 105 having the same diameter on both sides of the imaginary center line of two circular marks 105 are arranged parallel to the imaginary ball hitting line direction 109. Accordingly, the inclination of the imaginary center line of the circular marks 105, 105 with respect to the imaginary ball hitting line direction 109 at the take-back position and the follow-through position is increased and hence, the golfer tends to easily recognize the inclination of the imaginary center line of the circular marks 105 with his/her naked eyes. Accordingly, the golfer strongly feels the arcuate swinging of the putter head on the horizontal plane due to the inclination and this feeling damages his/her image to perform the stroke parallel to the imaginary ball hitting line direction 109.
FIG. 5 shows another type of conventionally known putter. As shown in FIG. 5, the putter includes a grip portion (not shown in the drawing) which is adapted to be grasped by a golfer, a shaft 100 extending linearly downward from the grip portion, and a putter head 107 which is connected to a distal end of the shaft 100. The putter head 107 has a laterally extending putter face ona front portion of a putter head body, a pair of triangular marks 103 which are formed on an upper surface of the putter head body and are arranged symmetrically with respect to an imaginary center line which extends rearwardly from a center (so-called “sweet spot”) 23 of the putter face 22 in the direction orthogonal to the putter face 22, and a strip-like longitudinal line mark 104 which is formed between the pair of triangular marks 103.
Due to such a constitution, the putter allows the golfer to easily align the longitudinal line mark 104 with the imaginary ball hitting line direction 109. Further, when the above-mentioned longitudinal line mark 104 which emphasizes the longitudinal direction becomes long and conspicuous in the imaginary ball hitting line direction 109, the alignment of the longitudinal line mark 104 with the imaginary ball hitting line direction 109 maybe facilitated. However, in an actual putting operation to take back the putter head 107 straightly parallel to the imaginary ball hitting line 109 and, thereafter, to swing the putter head 107 forward straightly parallel to the imaginary ball hitting line direction 109, the larger the take-back or the follow-through becomes, the swing stroke is liable to take an arcuate trajectory in a horizontal plane in the same manner as the putter head shown in FIG. 3. In this case, the longer and the more conspicuous the longitudinal line mark 104, the inclination of the longitudinal line mark 104 with respect to the imaginary ball hitting line direction 109 at the take-back and the follow-through is increased and hence, the golfer tends to easily recognize the inclination of the longitudinal line mark 104 with his/her naked eyes. Accordingly, the golfer strongly feels the arcuate swinging of the putter head on the horizontal plane due to the inclination and this feeling damages his/her image to perform the stroke parallel to the imaginary ball hitting line direction. Although the putter head includes the pair of triangular marks 103, outer inclined profile lines thereof and corresponding outer profile lines of the putter head body make a large acute angle with respect to the longitudinal line mark 104 and hence, the triangular marks 103 have substantially no effect in blurring the arcuate trajectory of the longitudinal line mark 104 whereby the golfer tends to easily recognize the inclination of the longitudinal line mark 104 with his/her naked eyes.
The present invention has been made to overcome such drawbacks of the related art and it is an object of the present invention to provide a putter head which gives a sense of smooth and comfortable stroking to a golfer while allowing the golfer to hit a golf ball so that the golf ball accurately travel on an imaginary ball hitting line direction.